| Message ID | 20210720025105.103680-3-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: support page mapping percpu first chunk allocator | expand |
On Tue, Jul 20, 2021 at 10:51:04AM +0800, Kefeng Wang wrote: > Percpu embedded first chunk allocator is the firstly option, but it > could fails on ARM64, eg, > "percpu: max_distance=0x5fcfdc640000 too large for vmalloc space 0x781fefff0000" > "percpu: max_distance=0x600000540000 too large for vmalloc space 0x7dffb7ff0000" > "percpu: max_distance=0x5fff9adb0000 too large for vmalloc space 0x5dffb7ff0000" > > then we could meet "WARNING: CPU: 15 PID: 461 at vmalloc.c:3087 pcpu_get_vm_areas+0x488/0x838", > even the system could not boot successfully. > > Let's implement page mapping percpu first chunk allocator as a fallback > to the embedding allocator to increase the robustness of the system. It looks like x86, powerpc and sparc implement their own setup_per_cpu_areas(). I had a quick look on finding some commonalities but I think it's a lot more hassle to make a generic version out of them (powerpc looks the simplest though). I think we could add a generic variant with the arm64 support and later migrate other architectures to it if possible. The patch looks ok to me otherwise but I'd need an ack from Greg as it touches drivers/. BTW, do we need something similar for the non-NUMA setup_per_cpu_areas()? I can see this patch only enables NEED_PER_CPU_PAGE_FIRST_CHUNK if NUMA. Leaving the rest of the patch below for Greg. > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > arch/arm64/Kconfig | 4 ++ > drivers/base/arch_numa.c | 82 +++++++++++++++++++++++++++++++++++----- > 2 files changed, 76 insertions(+), 10 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index b5b13a932561..eacb5873ded1 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1045,6 +1045,10 @@ config NEED_PER_CPU_EMBED_FIRST_CHUNK > def_bool y > depends on NUMA > > +config NEED_PER_CPU_PAGE_FIRST_CHUNK > + def_bool y > + depends on NUMA > + > source "kernel/Kconfig.hz" > > config ARCH_SPARSEMEM_ENABLE > diff --git a/drivers/base/arch_numa.c b/drivers/base/arch_numa.c > index 4cc4e117727d..563b2013b75a 100644 > --- a/drivers/base/arch_numa.c > +++ b/drivers/base/arch_numa.c > @@ -14,6 +14,7 @@ > #include <linux/of.h> > > #include <asm/sections.h> > +#include <asm/pgalloc.h> > > struct pglist_data *node_data[MAX_NUMNODES] __read_mostly; > EXPORT_SYMBOL(node_data); > @@ -168,22 +169,83 @@ static void __init pcpu_fc_free(void *ptr, size_t size) > memblock_free_early(__pa(ptr), size); > } > > +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK > +static void __init pcpu_populate_pte(unsigned long addr) > +{ > + pgd_t *pgd = pgd_offset_k(addr); > + p4d_t *p4d; > + pud_t *pud; > + pmd_t *pmd; > + > + p4d = p4d_offset(pgd, addr); > + if (p4d_none(*p4d)) { > + pud_t *new; > + > + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); > + if (!new) > + goto err_alloc; > + p4d_populate(&init_mm, p4d, new); > + } > + > + pud = pud_offset(p4d, addr); > + if (pud_none(*pud)) { > + pmd_t *new; > + > + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); > + if (!new) > + goto err_alloc; > + pud_populate(&init_mm, pud, new); > + } > + > + pmd = pmd_offset(pud, addr); > + if (!pmd_present(*pmd)) { > + pte_t *new; > + > + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); > + if (!new) > + goto err_alloc; > + pmd_populate_kernel(&init_mm, pmd, new); > + } > + > + return; > + > +err_alloc: > + panic("%s: Failed to allocate %lu bytes align=%lx from=%lx\n", > + __func__, PAGE_SIZE, PAGE_SIZE, PAGE_SIZE); > +} > +#endif > + > void __init setup_per_cpu_areas(void) > { > unsigned long delta; > unsigned int cpu; > - int rc; > + int rc = -EINVAL; > + > + if (pcpu_chosen_fc != PCPU_FC_PAGE) { > + /* > + * Always reserve area for module percpu variables. That's > + * what the legacy allocator did. > + */ > + rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, > + PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, > + pcpu_cpu_distance, > + pcpu_fc_alloc, pcpu_fc_free); > +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK > + if (rc < 0) > + pr_warn("PERCPU: %s allocator failed (%d), falling back to page size\n", > + pcpu_fc_names[pcpu_chosen_fc], rc); > +#endif > + } > > - /* > - * Always reserve area for module percpu variables. That's > - * what the legacy allocator did. > - */ > - rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, > - PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, > - pcpu_cpu_distance, > - pcpu_fc_alloc, pcpu_fc_free); > +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK > + if (rc < 0) > + rc = pcpu_page_first_chunk(PERCPU_MODULE_RESERVE, > + pcpu_fc_alloc, > + pcpu_fc_free, > + pcpu_populate_pte); > +#endif > if (rc < 0) > - panic("Failed to initialize percpu areas."); > + panic("Failed to initialize percpu areas (err=%d).", rc); > > delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; > for_each_possible_cpu(cpu) > -- > 2.26.2
On 2021/8/1 23:53, Catalin Marinas wrote: > On Tue, Jul 20, 2021 at 10:51:04AM +0800, Kefeng Wang wrote: >> Percpu embedded first chunk allocator is the firstly option, but it >> could fails on ARM64, eg, >> "percpu: max_distance=0x5fcfdc640000 too large for vmalloc space 0x781fefff0000" >> "percpu: max_distance=0x600000540000 too large for vmalloc space 0x7dffb7ff0000" >> "percpu: max_distance=0x5fff9adb0000 too large for vmalloc space 0x5dffb7ff0000" >> >> then we could meet "WARNING: CPU: 15 PID: 461 at vmalloc.c:3087 pcpu_get_vm_areas+0x488/0x838", >> even the system could not boot successfully. >> >> Let's implement page mapping percpu first chunk allocator as a fallback >> to the embedding allocator to increase the robustness of the system. > It looks like x86, powerpc and sparc implement their own > setup_per_cpu_areas(). I had a quick look on finding some commonalities > but I think it's a lot more hassle to make a generic version out of them > (powerpc looks the simplest though). I think we could add a generic > variant with the arm64 support and later migrate other architectures to > it if possible. Ok, let's do it later, I could try to make some cleanup after the patchset is merged ;) > The patch looks ok to me otherwise but I'd need an ack from Greg as it > touches drivers/. the arch_numa is only used ARM64 and riscv, the NEED_PER_CPU_PAGE_FIRST_CHUNK is not enabled on RISCV, so it's no bad effect. > > BTW, do we need something similar for the non-NUMA > setup_per_cpu_areas()? I can see this patch only enables > NEED_PER_CPU_PAGE_FIRST_CHUNK if NUMA. > > Leaving the rest of the patch below for Greg. > >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> >> --- >> arch/arm64/Kconfig | 4 ++ >> drivers/base/arch_numa.c | 82 +++++++++++++++++++++++++++++++++++----- >> 2 files changed, 76 insertions(+), 10 deletions(-) >> >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >> index b5b13a932561..eacb5873ded1 100644 >> --- a/arch/arm64/Kconfig >> +++ b/arch/arm64/Kconfig >> @@ -1045,6 +1045,10 @@ config NEED_PER_CPU_EMBED_FIRST_CHUNK >> def_bool y >> depends on NUMA >> >> +config NEED_PER_CPU_PAGE_FIRST_CHUNK >> + def_bool y >> + depends on NUMA >> + >> source "kernel/Kconfig.hz" >> >> config ARCH_SPARSEMEM_ENABLE >> diff --git a/drivers/base/arch_numa.c b/drivers/base/arch_numa.c >> index 4cc4e117727d..563b2013b75a 100644 >> --- a/drivers/base/arch_numa.c >> +++ b/drivers/base/arch_numa.c >> @@ -14,6 +14,7 @@ >> #include <linux/of.h> >> >> #include <asm/sections.h> >> +#include <asm/pgalloc.h> >> >> struct pglist_data *node_data[MAX_NUMNODES] __read_mostly; >> EXPORT_SYMBOL(node_data); >> @@ -168,22 +169,83 @@ static void __init pcpu_fc_free(void *ptr, size_t size) >> memblock_free_early(__pa(ptr), size); >> } >> >> +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK >> +static void __init pcpu_populate_pte(unsigned long addr) >> +{ >> + pgd_t *pgd = pgd_offset_k(addr); >> + p4d_t *p4d; >> + pud_t *pud; >> + pmd_t *pmd; >> + >> + p4d = p4d_offset(pgd, addr); >> + if (p4d_none(*p4d)) { >> + pud_t *new; >> + >> + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); >> + if (!new) >> + goto err_alloc; >> + p4d_populate(&init_mm, p4d, new); >> + } >> + >> + pud = pud_offset(p4d, addr); >> + if (pud_none(*pud)) { >> + pmd_t *new; >> + >> + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); >> + if (!new) >> + goto err_alloc; >> + pud_populate(&init_mm, pud, new); >> + } >> + >> + pmd = pmd_offset(pud, addr); >> + if (!pmd_present(*pmd)) { >> + pte_t *new; >> + >> + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); >> + if (!new) >> + goto err_alloc; >> + pmd_populate_kernel(&init_mm, pmd, new); >> + } >> + >> + return; >> + >> +err_alloc: >> + panic("%s: Failed to allocate %lu bytes align=%lx from=%lx\n", >> + __func__, PAGE_SIZE, PAGE_SIZE, PAGE_SIZE); >> +} >> +#endif >> + >> void __init setup_per_cpu_areas(void) >> { >> unsigned long delta; >> unsigned int cpu; >> - int rc; >> + int rc = -EINVAL; >> + >> + if (pcpu_chosen_fc != PCPU_FC_PAGE) { >> + /* >> + * Always reserve area for module percpu variables. That's >> + * what the legacy allocator did. >> + */ >> + rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, >> + PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, >> + pcpu_cpu_distance, >> + pcpu_fc_alloc, pcpu_fc_free); >> +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK >> + if (rc < 0) >> + pr_warn("PERCPU: %s allocator failed (%d), falling back to page size\n", >> + pcpu_fc_names[pcpu_chosen_fc], rc); >> +#endif >> + } >> >> - /* >> - * Always reserve area for module percpu variables. That's >> - * what the legacy allocator did. >> - */ >> - rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, >> - PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, >> - pcpu_cpu_distance, >> - pcpu_fc_alloc, pcpu_fc_free); >> +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK >> + if (rc < 0) >> + rc = pcpu_page_first_chunk(PERCPU_MODULE_RESERVE, >> + pcpu_fc_alloc, >> + pcpu_fc_free, >> + pcpu_populate_pte); >> +#endif >> if (rc < 0) >> - panic("Failed to initialize percpu areas."); >> + panic("Failed to initialize percpu areas (err=%d).", rc); >> >> delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; >> for_each_possible_cpu(cpu) >> -- >> 2.26.2 > . >
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b5b13a932561..eacb5873ded1 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1045,6 +1045,10 @@ config NEED_PER_CPU_EMBED_FIRST_CHUNK def_bool y depends on NUMA +config NEED_PER_CPU_PAGE_FIRST_CHUNK + def_bool y + depends on NUMA + source "kernel/Kconfig.hz" config ARCH_SPARSEMEM_ENABLE diff --git a/drivers/base/arch_numa.c b/drivers/base/arch_numa.c index 4cc4e117727d..563b2013b75a 100644 --- a/drivers/base/arch_numa.c +++ b/drivers/base/arch_numa.c @@ -14,6 +14,7 @@ #include <linux/of.h> #include <asm/sections.h> +#include <asm/pgalloc.h> struct pglist_data *node_data[MAX_NUMNODES] __read_mostly; EXPORT_SYMBOL(node_data); @@ -168,22 +169,83 @@ static void __init pcpu_fc_free(void *ptr, size_t size) memblock_free_early(__pa(ptr), size); } +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK +static void __init pcpu_populate_pte(unsigned long addr) +{ + pgd_t *pgd = pgd_offset_k(addr); + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + + p4d = p4d_offset(pgd, addr); + if (p4d_none(*p4d)) { + pud_t *new; + + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + if (!new) + goto err_alloc; + p4d_populate(&init_mm, p4d, new); + } + + pud = pud_offset(p4d, addr); + if (pud_none(*pud)) { + pmd_t *new; + + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + if (!new) + goto err_alloc; + pud_populate(&init_mm, pud, new); + } + + pmd = pmd_offset(pud, addr); + if (!pmd_present(*pmd)) { + pte_t *new; + + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + if (!new) + goto err_alloc; + pmd_populate_kernel(&init_mm, pmd, new); + } + + return; + +err_alloc: + panic("%s: Failed to allocate %lu bytes align=%lx from=%lx\n", + __func__, PAGE_SIZE, PAGE_SIZE, PAGE_SIZE); +} +#endif + void __init setup_per_cpu_areas(void) { unsigned long delta; unsigned int cpu; - int rc; + int rc = -EINVAL; + + if (pcpu_chosen_fc != PCPU_FC_PAGE) { + /* + * Always reserve area for module percpu variables. That's + * what the legacy allocator did. + */ + rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, + PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, + pcpu_cpu_distance, + pcpu_fc_alloc, pcpu_fc_free); +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK + if (rc < 0) + pr_warn("PERCPU: %s allocator failed (%d), falling back to page size\n", + pcpu_fc_names[pcpu_chosen_fc], rc); +#endif + } - /* - * Always reserve area for module percpu variables. That's - * what the legacy allocator did. - */ - rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, - PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, - pcpu_cpu_distance, - pcpu_fc_alloc, pcpu_fc_free); +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK + if (rc < 0) + rc = pcpu_page_first_chunk(PERCPU_MODULE_RESERVE, + pcpu_fc_alloc, + pcpu_fc_free, + pcpu_populate_pte); +#endif if (rc < 0) - panic("Failed to initialize percpu areas."); + panic("Failed to initialize percpu areas (err=%d).", rc); delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; for_each_possible_cpu(cpu)
Percpu embedded first chunk allocator is the firstly option, but it could fails on ARM64, eg, "percpu: max_distance=0x5fcfdc640000 too large for vmalloc space 0x781fefff0000" "percpu: max_distance=0x600000540000 too large for vmalloc space 0x7dffb7ff0000" "percpu: max_distance=0x5fff9adb0000 too large for vmalloc space 0x5dffb7ff0000" then we could meet "WARNING: CPU: 15 PID: 461 at vmalloc.c:3087 pcpu_get_vm_areas+0x488/0x838", even the system could not boot successfully. Let's implement page mapping percpu first chunk allocator as a fallback to the embedding allocator to increase the robustness of the system. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- arch/arm64/Kconfig | 4 ++ drivers/base/arch_numa.c | 82 +++++++++++++++++++++++++++++++++++----- 2 files changed, 76 insertions(+), 10 deletions(-)